Is it obligatory to inform the questioner about a change in a fatwa after having previously answered them with a fatwa supported by evidence, and then the mufti discovers that another opinion is more preponderant?

Scholars have differed on whether it is obligatory for a mujtahid (independent jurist) to inform the person he gave a fatwa (religious edict) to about a change in his ijtihad (independent reasoning). The more preponderant view is that it is obligatory for him to do so if the fatwa has not been acted upon and he can do so without difficulty. This falls under sincere advice (nasiha) and cooperation in righteousness and piety. However, if his ijtihad contradicts an authentic text or an explicit consensus, then he must inform the person he gave the fatwa to about the erroneous fatwa, because its sin falls upon the mufti (issuer of the fatwa), and because it is a certain error, and because of what Ibn Mas'ud (may Allah be pleased with him) did when he returned to the questioner and informed him of the error in the fatwa.